


Butterfly Effect

by KitaroBoi



Category: IDOLiSH7 (Video Game), Love Live! School Idol Project, Love Live! Sunshine!!
Genre: Alternate Universe - Feudal Japan, Bittersweet Ending, Blood and Injury, Character Death, Factions, Gen, Major Character Injury, Matter of Life and Death, Mild Language, Mythic Powers, OCs appear, Other Additional Tags to Be Added, Sad with a Happy Ending, Shounen Fights, Temporary Character Death, War, lore heavy
Language: English
Status: In-Progress
Published: 2020-11-26
Updated: 2021-01-07
Packaged: 2021-03-09 19:20:05
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 3
Words: 3,958
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27721304
Author URL: https://archiveofourown.org/users/KitaroBoi/pseuds/KitaroBoi
Summary: A war has broken out in the world as The Scourge spreads it's regime around Japan-- the face of the army being Kujou Tenn, a merciless killer known by many as the Angel of Death. As the war continues, resources run low as other factions try to fight against the regime in hopes that one day the peace will be restored.
Comments: 1
Kudos: 12





	1. Silence

**Author's Note:**

> WOW this fic is just a crazy mess of ideas but I promise I have a plan for this! It'll... just be a really long one. I've already written ahead quite a bit for this one so I'm really looking froward to releasing more chapters soon-- just... holy crap this was just something else. What started as an art my friend made (link in the notes at the end) has turned into a whole project!

_Silence. That was the only thing I felt on that morning in the aftermath of the night before. The rain felt like acid on my skin as the cursed black water rippled in the mist. The sky a dark red and the air around me fumed as I marched forward cold and emotionless. The groans of men dying around me and the sounds of the cries of women and children passed through one ear and out the other as I walked; all I felt was silence._

_I stood at the edge of the skirmish and looked down at a puddle mingled with the black of death and the red of lives soon lost. My light pink hair had turned gray and my eyes were shot red in the puddles reflection. I'd look like an ordinary man to many, if not a bit tired-- but anyone who lived through my scourge through some blessing (or curse) could tell you… I was anything but that._

_The rain grew heavier as my reflection became more muddled as I looked back at the field behind me. In past years I might’ve felt pain or hurt or sympathy in my wake, but now, all I felt was silence as I walked away. As a man I was Kujou Tenn, in reality, however, I am the Angel of Death._

**Chapter 1**

The soft sounds of the morning mist ring through the air as the routine sounds of the morning birds hushed by the quiet lullaby of the rain. Riku rolled over on the floor as he kept his eyes closed, snoring softly. The mist caked the world in a glistening layer of water. The mist remained the same yet the roar sounded like it was pouring-- the sky went dark yet the clouds remained still. 

Riku notices the noise and sits up, looking out the window. The sky was like an ocean as oil spilt into it-- streams of black streaming into the sky as all sense of light was filled with a deep opaque black. Riku coughs and wheezes, unable to handle the ash as he walks out-- the once mist-fills world caked in flame as a shadow scourges the village. Screams, prayers, cries all of them fill his ears as he limps out the village plaza. His chest tightens as his muscles freeze and his face hits the ground; coughing, wheezing, crying, Riku didn’t know what was happening. 

A person running from the scourge runs him over as he rolls to his side-- no one helps him, the only thing that matters is their own lives. Riku looked around as the shadow stood in front of him, staring down-- his glowing pink eye that wasn’t covered by a bandages shimmering in the flame to almost be like that of red. The gaze was cold, unloving, and apathetic. In one fell swoop he moves his hand and the sound of a slice rings through the air. Then-- pain, that was on the only thing Riku could discern as he sat there, unable to move. His world turns red as he cries in pain-- the warmth of his own blood seeping through his clothes-- he blacks out.

“...iku-kuuun~” a small quiet voice rings out through the void, “Riku-kuuuun~ It’s time for the--” with a gasp Riku startles awake and scans around. His eyes meet those of a red-head girl who looks at him with a gaze of innocent curiosity. He rubs his side and looks around to see he is in his room, on the floor… just like that vision he had. 

As his breathing stills he looks at the girl and cracks a smile, “Ehehe... Hey, Chika...sorry if I kept you waiting.” He rubs his eyes as he becomes more aware of his surroundings. _It’s not misting… the birds are chirping… everything seems pretty normal._

“Waiting…? You slept in for like-- 3 hours!” she said with a playful pout on her face, “It was honestly worrying-- you wouldn’t wake up no matter how hard I tried! Such a pain… hehe~” She jabbed at his arm before standing up and walking toward the entryway of his bedroom, “I’ll meet you outside, okay~?” 

“Sure… just give me a moment,” he giggles at her cheerful demeanor before heading to his chest and pulling out his outdoor kimono and putting it on as he walks out, “Sorry for taking so long~ Now, let’s head to the fields and do our part for a bit!” 

“Hai~” Chika says happily as she walks forward with her fist as if she was charging into battle. Riku chuckles as he walks forward and picks up a basket he uses for rice farming. Chika walks a small bit behind him with a skip in her step. With a happy hum she takes in the morning scenery as they head into the village plaza, the deep blue sky basically cloudless as she looks up at it. Once they reached the field they began their work. Since they were already late, they made less progress than usual because they still needed to head back to the village before night befell them. As Riku bent over she notices something and squints. 

  
“Say… Riku-kun, when did you get a tattoo?” 

“Eh? I don’t remember getting one-- plus why would I? Those things have a bad name nowadays anyways.” he said, still focused on his work. 

“Well… because…” she walks up to his neck and examines the mark on it. It was a butterfly with an extravagant pattern on the wings. Rays, lines dividing the wing like the sun slices through darkness with flames intermingling the pattern. A master artist would strive to achieve such work. Chika lightly touches it as she stares at it, “...it looks like you have on now…” 

“Eh…?” Riku said as he looks up with a face riddled with confusion and concern, “That can’t be I--” before he could finish the sentence he sees the image of a man dressed in loose-fitting clothing and parts of it sliced up-- his hair pink and his gaze lifeless with one eye covered by a bandage. Riku recognized him… it was the man in his dreams. The image disappears as soon as it faded, as Riku stares at the spot in which the man stood. His hands tremble as he stands there; he felt petrified by the man of his nightmare appearing so close to him.

“Riku-kun…?” Chika asks as she shakes Riku, but nothing reaches him in this moment, no sound, feeling sensation or emotion other than intense fear; all Riku could feel in this moment was silence. The silence before the storm. 


	2. The Mission

**Summary for the Chapter:**

> In the wake of the Scourge's rise to power the kingdom of Harvest begins to feel the impacts of Kujou Tenn's regime spreading across the land. Kitaro, the second-in-command at Harvest meets with Ann later that night to discuss the state of their people, and the steps that needed to be taken.

**Notes for the Chapter:**

> As shown by the tags, yes OCs do appear in the fic, albeit they play a fairly side-role to the main overarching plot! Since while I am the main person writing this, my friends and I wanted to have fun with some expanded characters to flesh out the world a bit~ This chapter was written in tandem with my good friend Ann (twitter: https://twitter.com/ann_teasocial) so I hope you enjoy this little transition chapter as it fleshes out the world a bit while the plot still starts!

Silence fills the night sky of a village as the moon shines on the roof of the shrine. Two people sit atop it, one has brown hair, with a small ponytail shooting off to the side, a gentle smile accompanying his gaze as he looks up to the moon. His deep brown eyes glistening in the moonlight as he thinks. The other, a girl, with a more confident smile and bright blue hair she sits next to the boy, her dual colored eyes of golden luster and a crystalizing ruby-like sheen shifted as she looked around at the peaceful sight.

The boy grabs a mug and some sake and takes a sip, his smile soon falling from his face, "As I'm sure you've noticed... trade routes are being blocked off or regulated like crazy. Our people are in trouble."

"Well tell me about it, I've had to send out more parties to deal with the aftermath than usual." The young woman's smile falls from her face at mention of the state of their kingdom, "Seems like lately The Scourge is out to obstruct us even more. I'd seriously like to just spear their god forsaken leader right about now."

She picks up her naginata which was resting beside her as usual, and draws a slightly tattered cloth from the pocket of her uniform, polishing the blade of the weapon. "It doesn't seem like they're a huge group of people, yet they've managed to trample so many of the villages and return them to nothing."

"No kidding... ever since the Iridescent Shade showed up an entire war broke out..." he says as he thinks back to a moment a few years back he first found a Shade. The glowing, mystical butterfly was enticing to say the least when he first looked upon it. He aimed to capture it, yet upon touching it he blacked out and the next thing he knew Dawn, the girl sitting next to him now, and his sister were the ones waking him up. 

Soon after they noticed a mark on the left side of his arm that showed a butterfly with a pattern-- each wing having a target. This was his Butterfly Effect as it seemed to be called now amongst those with similar circumstances. The boy sips the drink once more as he grumbled, "What's even worse is I don't even think it's their leader that's the real threat."

Dawn sighs and stands up, tossing the cloth to the side before swinging her weapon around to release her stress, all whilst still maintaining conversation with her consociate. "So you think that something else is manipulating them behind the scenes huh? To me it doesn't matter. They've done their damage, they've slaughtered countless people and ruined the lives of so many others. I don't care whether they're the real threats or not, they're still a threat to our kingdom, and I intend to end that." The female scowls, her attacks at the cool early spring air becoming more aggressive and sharp.

After a short while she stops, closing her eyes and allowing herself to calm down before she got too worked up over the situation. She makes her way back to the male who had been watching her with a composed air of maturity, and rubs her left shoulder blade, rolling it back and forth, stretching it out. Exactly where her own Butterfly Effect was. An elegant mark it was, the insect's wings splattered with black ink splotches of varying sizes. She recalls passing out after coming into contact with the Shade, only waking inside her room, her sister by her side.

"Well it matters because I think the target is actually hiding in plain sight. Too many small rebellions are going after this... Grand Scourge known as Takamasa Kujou... but I've been gathering some info on him and, there is literally nothing to suggest he's the one actually causing the damage," the boy says as he sets down his cup and pulls out an arrow from his quiver as he twirls it. 

"The real issue is the face of The Scourge's power itself... Kujou Tenn. Many villages refer to him as the Angel of Death; anywhere he goes being left in ruin, ash, blood, or a mix of the three. In fact, he's the reason I brought you up here today."

The 'Angel of Death'. Dawn had heard rumours of this man before. An exceedingly lethal and dangerous individual whom the people feared. "Ah, that name strikes a sense of familiarity. No matter how quick our troops are to his last scene of destruction, he leaves no evidence behind to his next location." The commander is still gripping her weapon, her hold becoming tighter and her knuckles becoming whiter, blending with the moon's rays upon their figures.

She's seen the damage that has been done to the villages she's checked upon. Every single one of them, destroyed and reduced to nothing. No crops, no houses, no life, no hope. The first time she had seen what one man could do, it honestly terrified her. How could a single person cause this much despair wherever he laid foot? As time passed it only fueled her desire to end him. If her naginata was going to kill one person, it would be Kujou Tenn. It was a vow that she made as a knight and a protector of the kingdom. Despite being the leader of Harvest's military forces, not once had Dawn taken the life of another human being, for it was against her moral code as warrior. However, this man. He tested that code. The day she would break would be the day she meets him on the battlefield.

"We have a few informants that are cluing us in on his next locations. As second-in-command to Harvest I am about to give an order; find Kujou Tenn and kill him. This war needs to end before the Scourge takes everyone’s lives, it’s only a matter of time the destruction becomes unrecoverable," With a sigh he tosses up his mug and then takes his bow, shooting through the wooden mug, the arrow embedded into the tree in the distance. 

"I know your code, but our kingdom is at risk... can I trust you to break the code just this once?"

Her face turns cold and determined. "Say no more. I swear as the lead protector of Harvest that I WILL be the one to kill him." The young woman rises to her feet once more, slamming the end of her spear onto the roof of the shrine, the metal against stone resonating in the silence of the night.

"By my blade he will perish for the anguish that he's caused our people. I refuse to have it any other way."

"Thank you, Dawn," he smiles kindly as he hops down from the shrine's rooftop, "Rest well, big day tomorrow," he adds as he walks away from the shrine. The Scourge had begun the war a little over a year ago now, bringing many of the kingdoms to ruin or close to it-- the boy, Kitaro, was determined to protect his people, no matter the cost. With a determined glare he looks up at the moon and sighs... knowing the real war's only just begun. 


	3. The Shrine

**Summary for the Chapter:**

> In the wake of seeing the man of his nightmare Riku passed out and thus forced Chika to take him home. While Riku was in a nightmare ridden slumber, Chika is working as his caregiver. Little do either of them know the shadow that lurks over their town.

**Notes for the Chapter:**

> HOLY CRAP it's been a bit in between chapters but I've really been trying to make this chapter the best it could be! Really hope you all enjoy it and I'll be writing a bit more consistently now! Excited for the next few chapters~! Enjoy!

_ All I felt was silence as I stared at the man in front of me in the field on that day before the Scourge arrived. The flickering image of the man through the flames that formed around him engraved in me as the world becomes blocked out. I felt nothing. I heard nothing. I was nothing. The man and I stared at each other through the flames as he held his katana in hand. His gaze was cold, devoid of emotion or anything resembling such. He didn’t move at all, the only thing moving was my heart as it slammed against my chest and the world around me that was already silent crashed down before my eyes. Soon there was nothing but darkness; my world turned to silence. _

__

**_Chapter 3: The Shrine_ **

When Riku wakes up in his room it is already night. He didn’t remember how he arrived there but he is panting frantically, out of breath from a panic attack he’d assume. He looks around and sees Chika laying there on the floor, passed out cold on the rug.

“Ah... I see...~” he says as he wryly chuckles and lays back down, his mind still on the dream he’d just had and what he saw earlier that day, “I wonder who that was...” he mumbles to himself as he drifts back to sleep, well tired having been passed out.

Later that night Chika awakens, a bit confused by the fog she had in her mind as she just wakes up. She then sees Riku and quickly remembers-- she brought him here after he passed out in the field. His breathing seems regular and his face no longer looks troubled as he coos quietly in his sleep. She lightly giggles as she looks at him before freezing at the sight of his neck.

With a shrill ring and a glow the mark on his neck alights, a flurry of rainbow colors flowing out as she stares at it, mesmerized by it. Then, in a flash, a glowing white butterfly appears and flutters around the room. It was enticing… something unlike she’d ever seen before. When it flutters its wings no air seems to move; the space it occupies is empty. As she leans forward to look at it closer she froze as she realizes what the quiet shrill sound flowing out of the creature was. Screams, cries, laughter, joy; feelings of heat, cold, wind and storm. All of these things began to fill her mind as she backed away from it, dizzy.

The butterfly itself merely floated around the room, with no particular destination in mind. Soon it returned back to Riku and melted into the mark on his neck, the tattoo now looking more normal. Chika, confused and stunned, gets up and begins to gather her things before leaving Riku’s home. The town is silent, due to it being well past the town’s curfew, meaning she knows she must move quickly. As she walks into the town square she notices something in the distance, a shadow on top of the trees... or so she thinks. Whenever she tries to focus on it it quickly vanishes into thin air before she can make out a shape.

She decides to begin running toward her home, however before she reaches there she sees something: a light white glow floating in her path. It flashes in and out with intensity as she walks closer to it, the shape becoming more clear; it is another butterfly. While similar to the one she had seen before it is definitely different. The one in Riku’s room had the sun on its wing but this one, in contrast simply has two eyes on its wing, creating a simple, yet unnerving aura to it. It begins to fly down the path slowly, as if leading her along as Chika follows it, wondering where it may lead. The pull of it almost made her forget the shadow she had just been running away from just moments before.

The butterfly moves into the foliage, all of it moving around it as the creature moves forward, creating a path to an old worn down shrine. The red poles like a pale pink from the wear, many of the shrine’s are broken, shattered or bloody. The butterfly’s glow becomes stronger here as the sounds of a thousand screams rings through the air. Chika flinches.

“What happened here...?” she whispers as she looks at the ripped clothes and remnants of priest’s jewelry scattered about. Fear sets in on Chika’s throat as she takes a nervous gulp and walks up the stairs to the place the village seemed to have all but forgotten. When she reaches the top of the stairs she gasps as the sight she beholds paralyzes her where she stood.

Skeletons, hanging on stakes, two males and two females. Any sign of their life clearly stripped from them as she sees them dangle in the breeze. The butterfly stops in the middle of the shrine, floating there, merely taking up space as it’s shrill ring becomes even more noticeable. As if in a trance Chika walks forward, her heart still struck with fear but yet she couldn’t seem to resist the desire as she reaches out and touches the butterfly.

In the twinkling of an eye the world goes white around her as she stands in the center of it. The white space soon darkening to show the shrine she was once at, restored and thriving, four people standing in the center. It is night, and they seem to be trying to keep their ritual a secret as they quietly sneak around and whisper. The words are indistinguishable to Chika, all coming out as shrill rings as they spoke.

A flash of red. One of the girls fell to the ground, bleeding as a cut across her chest soiled her attire. The shrill rings became piercing as the others scream and run around, trying to finish the ritual it seems. One more falls, without ever seeing the culprit, this time one of the men. Their procedure becomes sloppy as they run around and work rapidly. One of the men freezing before limply falling over, a cut from his back to his chest sealing his fate. All that was left was the last woman. Starting the incense the light from the candles reveal the girl had orange hair, not too unlike the shade of Chika’s. As the woman turns around her bright red eyes widen as she sees a shadow up on top of the shrine gate. Chika sees it too, as it hops down and brandishes it’s blade.

As it approaches, the shadow’s figure becomes more clear, revealing what seems to be a younger boy, pink hair flowing through the wind yet despite his youth his gaze was jaded and cynical. He stands in front of the woman and by proxy Chika as the first clear words Chika’s heard from the visions emerge, “...to the dogs with you.”

The boy then suddenly flashes as his right eye becomes covered with a bandage. His presence is more tangible as the shrine returns back to the state Chika remembers. It was then she realized that the same man was standing in front of her right now.

“Who are you?” she says, fear underscoring her otherwise confident exterior. The man slowly walks around her in a circle. His gaze is like stone and his presence is like ice. The words that come out of his mouth sound more like that of a deranged ghost than that of a human being.

“I’m an angel, from a certain point of view,” he replies, vague and indistinct. His tone was strange, almost aloof. The confidence within it was maddening as his gaze didn’t break.

“An angel? What type of angel kills four innocent people and leaves them to be stripped by the dogs!?” Chika asked, noticing her emotions are becoming more heated for some reason. Her skin is dripping with sweat as she finds it harder to stand. She then notices, on her hand, a glowing white mark; it was a butterfly with an eye on its wings. She gasps as he knees give out and she’s on all fours, bent over.

With a cold, unempathetic chuckle the man looks down on her, “You broke the barrier that woman put up, preventing me from ever finding or entering this village again. I guess for that I have to thank you...” he says as if he wanted to kill her, nay, he was looking forward to it, “Consider your life my grace to you.”

“G-Grace...?” she asks, finding it hard to breathe as her vision goes hazy.

“Yes, grace. I could kill you right here and now... the one... single... slice... But I don’t, since you’ve been of great service to me and Scourge~” another dry chuckle leaves his lips as he begins to walk away. Before he does, he turns back and eyes Chika down one more time, “The Day of Reckoning is upon your village, run while you can. I will show no more mercy to you from here on out.”

In a flash he disappears outside of an indistinct shadow fading in his aftermath. Chika tries to crawl forward but collapses and lands on her face. Unable to make out any shapes she tries to cry out, feeling like she is suffocating. She can only let out a tear before her world turns black around her and she lays there, unconscious at the shrine.

On a distant tree the man who was there watches as he smirks,  _ “Perhaps her Butterfly Effect might be useful~”  _ he thought as he began to climb down the tree,  _ “Maybe you’ll be more beneficial to me than just breaking the barrier... Chika.” _

__

**Author's Note:**

> Link to my friend's art that inspired this whole endeavor: 
> 
> The OG inspiration: https://twitter.com/ann_teasocial/status/1297738874030968832?s=20  
> Some brainrotting/OC designs: https://twitter.com/ann_teasocial/status/1331493576899846144?s=20


End file.
